Acoustically Absorptive Solid Volume Building Assembly

ABSTRACT

A building assembly, for use in a floor and/or ceiling of a building, consisting of a solid wood or mass timber structural panel layer, a lightweight panel layer, and an acoustically absorptive solid volume material layer between the solid wood or mass timber structural panel layer and the lightweight panel layer to provide a separation of an air-borne acoustic vibration or a separation of an impact- or structure-borne acoustic vibration between the lightweight panel layer and the solid wood or mass timber structural panel layer.

TECHNICAL FIELD

The invention relates to solid wood or mass timber-based floor panelassemblies that provide acoustic separation.

BACKGROUND

Prior art floor assemblies, such as traditional stick-framed floorassemblies, include high density vertical elements, such as wood-productbased floor joists (e.g., engineered wood joists) that couple to a toplayer of the floor, such as plywood subflooring, and to a bottom layerof the floor, such as ceiling material, e.g., gypsum, for a lower levelof a building. The vertical elements facilitate transfer of air-borneacoustic vibration and transfer of an impact- or structure-borneacoustic vibration between the top layer and the bottom layer. What isneeded is a floor assembly that lessens the transfer of air-borneacoustic vibration and transfer of an impact- or structure-borneacoustic vibration between the top layer and the bottom layer, forexample, by not using any high density vertical elements.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example, and not by way oflimitation, and can be more fully understood with reference to thefollowing detailed description when considered in connection with thefigures in which:

FIG. 1A illustrates an embodiment of the invention.

FIG. 1B illustrates an embodiment of the invention.

DETAILED DESCRIPTION

With reference to FIGS. 1A and 1B, embodiments of the invention 100A,100B involve a building assembly, for use in a floor, or ceiling, of abuilding. The assembly consists of a solid wood or mass timberstructural panel 105, for example, a cross-laminated timber (CLT) panellayer that serves as the supporting structure, a lightweight panel layer110, such as a wood product-based panel layer, or a cement product-basedpanel layer, or a combination thereof, and an acoustically absorptivesolid volume material layer 115 between the solid wood or mass timberstructural panel layer 105 and the lightweight panel layer 110 toprovide a separation of, a dampening in, or a decrease in a transfer ofair-borne acoustic vibration and/or to provide a separation of, adampening in, or a decrease in a transfer of an impact- orstructure-borne acoustic vibration between the lightweight panel layer110 and the solid wood or mass timber structural panel layer 105.Building assemblies according to the disclosed embodiments at least meetthe International Building Code (IBC) section 1207.2 requirements forfield sound transmission class (FSTC) and IBC section 1207.3requirements for field impact isolation class (FIIC).

In one embodiment, a building assembly using a mass timber structuralpanel layer 105 of 162 mm in thickness attains a sound transmissionclass (STC) rating of at least 50 for airborne sound separation, attainsa field sound transmission class (FSTC) rating of 45 for airborne soundseparation, attains an impact insulation class (IIC) rating of at least50 for impact sound separation, and attains a field impact insulationclass (FIIC) rating of at least 45 for impact sound separation.

In another embodiment, the building assembly using a mass timberstructural panel layer 105 of 140 mm in thickness attains a Field SoundTransmission Class rating in the range of 50-52. In this embodiment, thebuilding assembly attains an Apparent Impact Insulation Class rating inthe range of 47-50.

In one embodiment, the solid wood or mass timber structural panel layer105 in the building assemblies 100A, 100B includes a number of solidwood panel products fastened to each other to create a solid flat platestructural floor having a thickness in the range of 140-173 mm and aweight in the range of 14.2 to 16.4 pounds/square foot. In oneembodiment, the solid wood panel products fastened to each other iscross laminated timber (CLT) product having a number of layers (5 layersdepicted at 105 in FIGS. 1A, 1B). In various embodiments, each CLT layerhas a thickness in the range of 28 mm-34.6 mm and a weight in the rangeof 2.84 to 3.28 pounds/square foot.

In the embodiments, the solid wood or mass timber structural panel layer105 is capable of supporting, from a strength and serviceabilitystandpoint, a uniform building load of at least 100 pounds/square foot,and a concentrated building load of at least 2,000 pounds applied to alocalized area of 2.5 ft×2.5 ft. (These are requirements found inSection 1607 of the International Building Code (IBC) and encompassassembly, office, and residential loading requirements.)

In one embodiment, the solid wood or mass timber structural panel layer105 attains an Apparent Impact Insulation Class rating in the range of18-20 and attains a Field Sound Transmission Class rating in the rangeof 36-37.

The embodiment 100A of the building assembly uses a lightweight panellayer 110 made of a wood product-based panel layer, such as: a mediumdensity fiberboard (MDF) panel having a thickness of approximately ¾″and a weight in the range of 3.1 to 4.25 pounds/square foot, or a tongueand groove plywood panel having a thickness of approximately ¾″ and aweight of approximately 2.1 pounds/square foot. In the embodiment 100A,the building assembly further includes a tongue and groove plywood panelhaving a thickness of approximately ¾″ and a weight of approximately 2.1pounds/square foot fastened to (e.g., screwed to) the wood product-basedpanel layer.

The embodiment 100B of the building assembly uses a lightweight panellayer 110 made of a particleboard panel having a thickness ofapproximately 1″ and a weight of approximately 4.25 pounds/square foot.In the embodiment 100B, the building assembly further includes a plywoodpanel having a thickness of approximately ½″ and a weight ofapproximately 1.5 pounds/square foot fastened to the particleboardpanel. Alternatively, the embodiment 100B of the building assembly usesa lightweight panel layer 110 made of a number of layers of structuralboard. In the embodiment, each structural board is made of cellulosefiber having a thickness of approximately ⅝″ (e.g., ⅝″ Homasote 440SoundBarrier™ panels) and a weight of approximately 1.5 pounds/squarefoot.

The embodiment 100B of the building assembly further includes anotherlayer 125 of the structural board, or a plywood panel having a thicknessof approximately ½″ and a weight of approximately 1.5 pounds/squarefoot, fastened to the layers of structural board.

One embodiment of the invention contemplates the building assembly usinga lightweight panel layer 110 made of a cement product-based panellayer, such as cement board. In one embodiment, multiple layers ofcement board may be used, each having a thickness varying between ¼″ to1″.

In the building assembly of the embodiments of the invention, theacoustically absorptive solid volume material layer 115 is sandwichedbetween the solid wood or mass timber structural panel layer 105 and thelightweight panel layer 110. In one embodiment, the layer is made of oneor more compressed mineral wool insulation boards. In one embodiment,there are 3 boards each 1″ in thickness, wherein the overall thicknessof the layer 115 is approximately 3″ and weighs approximately 3⅛pounds/square foot. In one embodiment, the layer consists of ahigh-density, stone wool insulation board, e.g., Roxul® Monoboard®, or ahigh-density uncoated stone wool insulation board, e.g., Roxul® TopRock®DD, or an equivalent product. Importantly, the acoustically absorptivesolid volume material layer 115 transfers a uniform structural loadand/or a concentrated structural load applied to the lightweight panellayer 110 from the lightweight panel layer 110 to the solid wood or masstimber structural panel layer 105.

The building assembly according to embodiment 100A may further include aplywood subfloor 125 adjacent an outside surface of the lightweightpanel layer 110. It is contemplated that a floor topping treatment isapplied to the building assembly of the variously described embodiments.This floor topping treatment may be a finished floor material 130adjacent an outside surface of the plywood subfloor 125. Such finishedfloor material might be carpeting, a carpet pad, tile, vinyl, or ceramictile.

Advantageously, the building assembly in the described embodiments maybe manufactured off-site as a number of standard sized modular panels of4′×8′, or larger dimensions, which are then shipped to a building sitefor installation and use in the floor and/or ceiling of the building.

Embodiments of the invention contemplate a floor topping (e.g., carpet,carpet pad, tile, vinyl, etc.) treatment. Such floor topping treatmentsare not integral to the acoustic rated assembly in the describedembodiments, that is, the embodiments described herein meet the codeminimum requirements without applying the floor topping treatments.However, applying a finish floor product to the embodiments of theinvention will further improve the impact acoustic performance of thedescribed embodiments.

One embodiment of the invention also incorporates design elements suchas exposing the underside of the solid wood or mass timber structuralpanel layer for architectural and aesthetic reasons, and avoiding theuse of a wet trade cement-based product(s), such as gyperete, to improveconstructability and efficiency.

Embodiments of the invention were tested for both airborne and impactsound isolation utilizing the methods outlined in ASTM E336: StandardMethod for Measurement of Airborne Sound Insulation in Buildings andASTM E1007: Standard Test Method for Field Measurement of TappingMachine Impact Sound Transmission Through Floor-Ceiling Assemblies andAssociated Support Structures to characterize the airborne and impactnoise isolation performance of the embodiments.

Embodiments of the invention meet the International Building Code (IBC)section 1207.2 requirements for field sound transmission class (FSTC)and IBC section 1207.3 requirements for field impact isolation class(FIIC). Per IBC section 1207.1, these requirements apply to commoninterior walls, partitions and floor/ceiling assemblies between adjacentdwelling units and sleeping units or between dwelling units and sleepingunits and adjacent public areas such as halls, corridors, stairways orservice areas. Section 1207.2 requires that walls, partitions andfloor/ceiling assemblies separating dwelling units and sleeping unitsfrom each other or from public or service areas shall have a soundtransmission class of not less than 50 if laboratory tested, or not lessthan 45 if field tested, for air-borne noise when tested in accordancewith ASTM E 90. Penetrations or openings in construction assemblies forpiping; electrical devices; recessed cabinets; bathtubs, soffits; orheating, ventilating or exhaust ducts shall be sealed, lined, insulatedor otherwise treated to maintain the required ratings. Section 1207.3requires that floor/ceiling assemblies between dwelling units andsleeping units or between a dwelling unit or sleeping unit and a publicor service area within the structure shall have an impact insulationclass rating of not less than 50 if laboratory tested, or not less than45 if field tested, when tested in accordance with ASTM E 492.

Although embodiments of the invention have been described andillustrated in the foregoing illustrative embodiments, it is understoodthat present disclosure has been made only by way of example, and thatnumerous changes in the details of implementation of the invention canbe made without departing from the spirit and scope of embodiments ofthe invention, which is only limited by the claims that follow. Featuresof the disclosed embodiments can be combined and rearranged in variousways.

1. A building assembly, for use in a floor and/or ceiling of a building,consisting of: a solid wood or mass timber structural panel layer; alightweight panel layer; and an acoustically absorptive solid volumematerial layer between the solid wood or mass timber structural panellayer and the lightweight panel layer to provide a separation of anair-borne acoustic vibration or a separation of an impact- orstructure-borne acoustic vibration between the lightweight panel layerand the solid wood or mass timber structural panel layer.
 2. Thebuilding assembly of claim 1, wherein the building assembly meets theInternational Building Code (IBC) section 1207.2 requirements for fieldsound transmission class (FSTC) and IBC section 1207.3 requirements forfield impact isolation class (FIIC).
 3. The building assembly of claim1, wherein the building assembly attains a sound transmission class(STC) rating of at least 50 for airborne sound separation, attains afield sound transmission class (FSTC) rating of 45 for airborne soundseparation, attains an impact insulation class (IIC) rating of at least50 for impact sound separation, and attains a field impact insulationclass (FIIC) rating of at least 45 for impact sound separation.
 4. Thebuilding assembly of claim 1, wherein the building assembly attains aField Sound Transmission Class rating in the range of 50-52.
 5. Thebuilding assembly of claim 1, wherein the building assembly attains anApparent Impact Insulation Class rating in the range of 47-50.
 6. Thebuilding assembly of claim 1, wherein the solid wood or mass timberstructural panel layer comprises a plurality of solid wood panelproducts fastened to each other to create a solid flat plate structuralfloor having a thickness in the range of 140-173 mm and a weight in therange of 14.2 to 16.4 pounds/square foot.
 7. The building assembly ofclaim 6, wherein the plurality of solid wood panel products fastened toeach other to create the solid flat plate structural floor comprises across laminated timber product having a plurality of layers, each layerhaving a thickness in the range of 28 mm-34.6 mm and a weight in therange of 2.84 to 3.28 pounds/square foot.
 8. The building assembly ofclaim 1, wherein the solid wood or mass timber structural panel layer iscapable of supporting a uniform building load of at least 100pounds/square foot, and a concentrated building load of at least 2,000pounds applied to a localized area of 2.5 ft×2.5 ft.
 9. The buildingassembly of claim 1, wherein the solid wood or mass timber structuralpanel layer attains an Apparent Impact Insulation Class rating in therange of 18-20 and attains a Field Sound Transmission Class rating inthe range of 36-37.
 10. The building assembly of claim 1, wherein thelightweight panel layer comprises a wood product-based panel layer. 11.The building assembly of claim 10, wherein the wood product-based panellayer is selected from a group consisting of: a medium densityfiberboard (MDF) panel having a thickness of approximately ¾″ and aweight in the range of 3.1 to 4.25 pounds/square foot; and a tongue andgroove plywood panel having a thickness of approximately ¾″ and a weightof approximately 2.1 pounds/square foot.
 12. The building assembly ofclaim 10, further comprising a tongue and groove plywood panel having athickness of approximately ¾″ and a weight of approximately 2.1pounds/square foot fastened to (e.g., screwed to) the wood product-basedpanel layer.
 13. The building assembly of claim 1, wherein thelightweight panel layer comprises a particleboard panel having athickness of approximately 1″ and a weight of approximately 4.25pounds/square foot.
 14. The building assembly of claim 13, furthercomprising a plywood panel having a thickness of approximately ½″ and aweight of approximately 1.5 pounds/square foot fastened to theparticleboard panel.
 15. The building assembly of claim 1, wherein thelightweight panel layer comprises a plurality of layers of structuralboard, each structural board comprising cellulose fiber having athickness of approximately ⅝″ and a weight of approximately 1.5pounds/square foot.
 16. The building assembly of claim 15, furthercomprising another layer of the structural board, or a plywood panelhaving a thickness of approximately ½″ and a weight of approximately 1.5pounds/square foot, fastened to the plurality of layers of structuralboard.
 17. The building assembly of claim 1, wherein the lightweightpanel layer comprises a cement product-based panel layer.
 18. Thebuilding assembly of claim 1, wherein the acoustically absorptive solidvolume material layer between the solid wood or mass timber structuralpanel layer and the lightweight panel layer comprises a plurality ofcompressed mineral wool insulation boards having an overall thickness ofapproximately 3″ and a weight of approximately 3⅛ pounds/square foot.19. The building assembly of claim 1, further comprising a plywoodsubfloor adjacent an outside surface of the lightweight panel layer. 20.(canceled)
 21. The building assembly of claim 1, wherein the buildingassembly is to be manufactured off-site as a plurality of panels forshipment to a building site for use in the floor and/or ceiling of thebuilding.
 22. The building assembly of claim 1, wherein the acousticallyabsorptive solid volume material layer is to transfer a uniformstructural load and/or a concentrated structural load applied to thelightweight panel layer from the lightweight panel layer to the solidwood or mass timber structural panel layer.